System and method for supporting wire efficient replication using self-descriptive data buffer

ABSTRACT

A method, computer program product, and computer system for receiving, by a computing device, an IO request. It may be determined that data of the IO request includes an indication of an attribute. A prefix descriptor may be constructed for the data in a self-descriptive page buffer based upon, at least in part, determining that the data of the IO request includes the indication of the attribute. An appropriate Application Programming Interface (API) may be called to process the IO request based upon, at least in part, the prefix descriptor.

BACKGROUND

The next generation of storage arrays (e.g., midrange storage arrays)may support a rich set of data efficiency features, includingdeduplication, compression, pattern detection, etc. With the dataefficiency features, data may be stored in persistent media in the mostefficient form. When replicating or migrating the data, it may bebeneficial to preserve the data in its efficient form, to save networkbandwidth, to speed up replication data transfer, and to potentiallysave precious storage system CPU and memory resources from duplicatingdata efficiency effort at a replication target.

BRIEF SUMMARY OF DISCLOSURE

In one example implementation, a method, performed by one or morecomputing devices, may include but is not limited to receiving, by acomputing device, an IO request. It may be determined that data of theIO request includes an indication of an attribute. A prefix descriptormay be constructed for the data in a self-descriptive page buffer basedupon, at least in part, determining that the data of the IO requestincludes the indication of the attribute. An appropriate ApplicationProgramming Interface (API) may be called to process the IO requestbased upon, at least in part, the prefix descriptor.

One or more of the following example features may be included. Theappropriate API may be a write compressed API when the prefix descriptorindicates compressed data. A bitmap of the self-descriptive page bufferand length of the self-descriptive page buffer may be checked. Theprefix descriptor may be added to the data in the self-descriptive pagebuffer after compression of the data. The prefix descriptor may includea type of the attribute, wherein the attribute may include an indicationwhether the data is a known pattern. The prefix descriptor may include atype of the attribute, wherein the attribute may include an indicationwhether the data is deduplicated. The prefix descriptor may include atype of the attribute, wherein the attribute may include an indicationwhether the data is compressed.

In another example implementation, a computing system may include one ormore processors and one or more memories configured to performoperations that may include but are not limited to receiving an IOrequest. It may be determined that data of the IO request includes anindication of an attribute. A prefix descriptor may be constructed forthe data in a self-descriptive page buffer based upon, at least in part,determining that the data of the IO request includes the indication ofthe attribute. An appropriate Application Programming Interface (API)may be called to process the IO request based upon, at least in part,the prefix descriptor.

One or more of the following example features may be included. Theappropriate API may be a write compressed API when the prefix descriptorindicates compressed data. A bitmap of the self-descriptive page bufferand length of the self-descriptive page buffer may be checked. Theprefix descriptor may be added to the data in the self-descriptive pagebuffer after compression of the data. The prefix descriptor may includea type of the attribute, wherein the attribute may include an indicationwhether the data is a known pattern. The prefix descriptor may include atype of the attribute, wherein the attribute may include an indicationwhether the data is deduplicated. The prefix descriptor may include atype of the attribute, wherein the attribute may include an indicationwhether the data is compressed.

In another example implementation, a computer program product may resideon a computer readable storage medium having a plurality of instructionsstored thereon which, when executed across one or more processors, maycause at least a portion of the one or more processors to performoperations that may include but are not limited to receiving an IOrequest. It may be determined that data of the IO request includes anindication of an attribute. A prefix descriptor may be constructed forthe data in a self-descriptive page buffer based upon, at least in part,determining that the data of the IO request includes the indication ofthe attribute. An appropriate Application Programming Interface (API)may be called to process the IO request based upon, at least in part,the prefix descriptor.

One or more of the following example features may be included. Theappropriate API may be a write compressed API when the prefix descriptorindicates compressed data. A bitmap of the self-descriptive page bufferand length of the self-descriptive page buffer may be checked. Theprefix descriptor may be added to the data in the self-descriptive pagebuffer after compression of the data. The prefix descriptor may includea type of the attribute, wherein the attribute may include an indicationwhether the data is a known pattern. The prefix descriptor may include atype of the attribute, wherein the attribute may include an indicationwhether the data is deduplicated. The prefix descriptor may include atype of the attribute, wherein the attribute may include an indicationwhether the data is compressed.

The details of one or more example implementations are set forth in theaccompanying drawings and the description below. Other possible examplefeatures and/or possible example advantages will become apparent fromthe description, the drawings, and the claims. Some implementations maynot have those possible example features and/or possible exampleadvantages, and such possible example features and/or possible exampleadvantages may not necessarily be required of some implementations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an example diagrammatic view of a IO process coupled to anexample distributed computing network according to one or more exampleimplementations of the disclosure;

FIG. 2 is an example diagrammatic view of a storage system of FIG. 1according to one or more example implementations of the disclosure;

FIG. 3 is an example diagrammatic view of a storage target of FIG. 1according to one or more example implementations of the disclosure; and

FIG. 4 is an example flowchart of a IO process according to one or moreexample implementations of the disclosure.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

System Overview:

In some implementations, the present disclosure may be embodied as amethod, system, or computer program product. Accordingly, in someimplementations, the present disclosure may take the form of an entirelyhardware implementation, an entirely software implementation (includingfirmware, resident software, micro-code, etc.) or an implementationcombining software and hardware aspects that may all generally bereferred to herein as a “circuit,” “module” or “system.” Furthermore, insome implementations, the present disclosure may take the form of acomputer program product on a computer-usable storage medium havingcomputer-usable program code embodied in the medium.

In some implementations, any suitable computer usable or computerreadable medium (or media) may be utilized. The computer readable mediummay be a computer readable signal medium or a computer readable storagemedium. The computer-usable, or computer-readable, storage medium(including a storage device associated with a computing device or clientelectronic device) may be, for example, but is not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus, device, or any suitable combination ofthe foregoing. More specific examples (a non-exhaustive list) of thecomputer-readable medium may include the following: an electricalconnection having one or more wires, a portable computer diskette, ahard disk, a random access memory (RAM), a read-only memory (ROM), anerasable programmable read-only memory (EPROM or Flash memory), anoptical fiber, a portable compact disc read-only memory (CD-ROM), anoptical storage device, a digital versatile disk (DVD), a static randomaccess memory (SRAM), a memory stick, a floppy disk, a mechanicallyencoded device such as punch-cards or raised structures in a groovehaving instructions recorded thereon, a media such as those supportingthe internet or an intranet, or a magnetic storage device. Note that thecomputer-usable or computer-readable medium could even be a suitablemedium upon which the program is stored, scanned, compiled, interpreted,or otherwise processed in a suitable manner, if necessary, and thenstored in a computer memory. In the context of the present disclosure, acomputer-usable or computer-readable, storage medium may be any tangiblemedium that can contain or store a program for use by or in connectionwith the instruction execution system, apparatus, or device.

In some implementations, a computer readable signal medium may include apropagated data signal with computer readable program code embodiedtherein, for example, in baseband or as part of a carrier wave. In someimplementations, such a propagated signal may take any of a variety offorms, including, but not limited to, electro-magnetic, optical, or anysuitable combination thereof. In some implementations, the computerreadable program code may be transmitted using any appropriate medium,including but not limited to the internet, wireline, optical fibercable, RF, etc. In some implementations, a computer readable signalmedium may be any computer readable medium that is not a computerreadable storage medium and that can communicate, propagate, ortransport a program for use by or in connection with an instructionexecution system, apparatus, or device.

In some implementations, computer program code for carrying outoperations of the present disclosure may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Java®, Smalltalk, C++ or the like.Java® and all Java-based trademarks and logos are trademarks orregistered trademarks of Oracle and/or its affiliates. However, thecomputer program code for carrying out operations of the presentdisclosure may also be written in conventional procedural programminglanguages, such as the “C” programming language, PASCAL, or similarprogramming languages, as well as in scripting languages such asJavascript, PERL, or Python. The program code may execute entirely onthe user's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer or server. In the latterscenario, the remote computer may be connected to the user's computerthrough a local area network (LAN) or a wide area network (WAN), or theconnection may be made to an external computer (for example, through theinternet using an Internet Service Provider). In some implementations,electronic circuitry including, for example, programmable logiccircuitry, field-programmable gate arrays (FPGAs) or other hardwareaccelerators, micro-controller units (MCUs), or programmable logicarrays (PLAs) may execute the computer readable programinstructions/code by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present disclosure.

In some implementations, the flowchart and block diagrams in the figuresillustrate the architecture, functionality, and operation of possibleimplementations of apparatus (systems), methods and computer programproducts according to various implementations of the present disclosure.Each block in the flowchart and/or block diagrams, and combinations ofblocks in the flowchart and/or block diagrams, may represent a module,segment, or portion of code, which comprises one or more executablecomputer program instructions for implementing the specified logicalfunction(s)/act(s). These computer program instructions may be providedto a processor of a general purpose computer, special purpose computer,or other programmable data processing apparatus to produce a machine,such that the computer program instructions, which may execute via theprocessor of the computer or other programmable data processingapparatus, create the ability to implement one or more of thefunctions/acts specified in the flowchart and/or block diagram block orblocks or combinations thereof. It should be noted that, in someimplementations, the functions noted in the block(s) may occur out ofthe order noted in the figures (or combined or omitted). For example,two blocks shown in succession may, in fact, be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved.

In some implementations, these computer program instructions may also bestored in a computer-readable memory that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the function/act specified in the flowchart and/or blockdiagram block or blocks or combinations thereof.

In some implementations, the computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operational steps to be performed (not necessarilyin a particular order) on the computer or other programmable apparatusto produce a computer implemented process such that the instructionswhich execute on the computer or other programmable apparatus providesteps for implementing the functions/acts (not necessarily in aparticular order) specified in the flowchart and/or block diagram blockor blocks or combinations thereof.

Referring now to the example implementation of FIG. 1, there is shown IOprocess 10 that may reside on and may be executed by a computer (e.g.,computer 12), which may be connected to a network (e.g., network 14)(e.g., the internet or a local area network). Examples of computer 12(and/or one or more of the client electronic devices noted below) mayinclude, but are not limited to, a storage system (e.g., a NetworkAttached Storage (NAS) system, a Storage Area Network (SAN)), a personalcomputer(s), a laptop computer(s), mobile computing device(s), a servercomputer, a series of server computers, a mainframe computer(s), or acomputing cloud(s). As is known in the art, a SAN may include one ormore of the client electronic devices, including a RAID device and a NASsystem. In some implementations, each of the aforementioned may begenerally described as a computing device. In certain implementations, acomputing device may be a physical or virtual device. In manyimplementations, a computing device may be any device capable ofperforming operations, such as a dedicated processor, a portion of aprocessor, a virtual processor, a portion of a virtual processor,portion of a virtual device, or a virtual device. In someimplementations, a processor may be a physical processor or a virtualprocessor. In some implementations, a virtual processor may correspondto one or more parts of one or more physical processors. In someimplementations, the instructions/logic may be distributed and executedacross one or more processors, virtual or physical, to execute theinstructions/logic. Computer 12 may execute an operating system, forexample, but not limited to, Microsoft® Windows®; Mac® OS X®; Red Hat®Linux®, Windows® Mobile, Chrome OS, Blackberry OS, Fire OS, or a customoperating system. (Microsoft and Windows are registered trademarks ofMicrosoft Corporation in the United States, other countries or both; Macand OS X are registered trademarks of Apple Inc. in the United States,other countries or both; Red Hat is a registered trademark of Red HatCorporation in the United States, other countries or both; and Linux isa registered trademark of Linus Torvalds in the United States, othercountries or both).

In some implementations, as will be discussed below in greater detail, aIO process, such as IO process 10 of FIG. 1, may receive, by a computingdevice, an IO request. It may be determined that data of the IO requestincludes an indication of an attribute. A prefix descriptor may beconstructed for the data in a self-descriptive page buffer based upon,at least in part, determining that the data of the IO request includesthe indication of the attribute. An appropriate Application ProgrammingInterface (API) may be called to process the IO request based upon, atleast in part, the prefix descriptor.

In some implementations, the instruction sets and subroutines of IOprocess 10, which may be stored on storage device, such as storagedevice 16, coupled to computer 12, may be executed by one or moreprocessors and one or more memory architectures included within computer12. In some implementations, storage device 16 may include but is notlimited to: a hard disk drive; all forms of flash memory storagedevices; a tape drive; an optical drive; a RAID array (or other array);a random access memory (RAM); a read-only memory (ROM); or combinationthereof. In some implementations, storage device 16 may be organized asan extent, an extent pool, a RAID extent (e.g., an example 4D+1P R5,where the RAID extent may include, e.g., five storage device extentsthat may be allocated from, e.g., five different storage devices), amapped RAID (e.g., a collection of RAID extents), or combinationthereof.

In some implementations, network 14 may be connected to one or moresecondary networks (e.g., network 18), examples of which may include butare not limited to: a local area network; a wide area network or othertelecommunications network facility; or an intranet, for example. Thephrase “telecommunications network facility,” as used herein, may referto a facility configured to transmit, and/or receive transmissionsto/from one or more mobile client electronic devices (e.g., cellphones,etc.) as well as many others.

In some implementations, computer 12 may include a data store, such as adatabase (e.g., relational database, object-oriented database,triplestore database, etc.) and may be located within any suitablememory location, such as storage device 16 coupled to computer 12. Insome implementations, data, metadata, information, etc. describedthroughout the present disclosure may be stored in the data store. Insome implementations, computer 12 may utilize any known databasemanagement system such as, but not limited to, DB2, in order to providemulti-user access to one or more databases, such as the above notedrelational database. In some implementations, the data store may also bea custom database, such as, for example, a flat file database or an XMLdatabase. In some implementations, any other form(s) of a data storagestructure and/or organization may also be used. In some implementations,IO process 10 may be a component of the data store, a standaloneapplication that interfaces with the above noted data store and/or anapplet/application that is accessed via client applications 22, 24, 26,28. In some implementations, the above noted data store may be, in wholeor in part, distributed in a cloud computing topology. In this way,computer 12 and storage device 16 may refer to multiple devices, whichmay also be distributed throughout the network.

In some implementations, computer 12 may execute a storage managementapplication (e.g., storage management application 21), examples of whichmay include, but are not limited to, e.g., a storage system application,a cloud computing application, a data synchronization application, adata migration application, a garbage collection application, or otherapplication that allows for the implementation and/or management of datain a clustered (or non-clustered) environment (or the like). In someimplementations, IO process 10 and/or storage management application 21may be accessed via one or more of client applications 22, 24, 26, 28.In some implementations, IO process 10 may be a standalone application,or may be an applet/application/script/extension that may interact withand/or be executed within storage management application 21, a componentof storage management application 21, and/or one or more of clientapplications 22, 24, 26, 28. In some implementations, storage managementapplication 21 may be a standalone application, or may be anapplet/application/script/extension that may interact with and/or beexecuted within IO process 10, a component of IO process 10, and/or oneor more of client applications 22, 24, 26, 28. In some implementations,one or more of client applications 22, 24, 26, 28 may be a standaloneapplication, or may be an applet/application/script/extension that mayinteract with and/or be executed within and/or be a component of IOprocess 10 and/or storage management application 21. Examples of clientapplications 22, 24, 26, 28 may include, but are not limited to, e.g., astorage system application, a cloud computing application, a datasynchronization application, a data migration application, a garbagecollection application, or other application that allows for theimplementation and/or management of data in a clustered (ornon-clustered) environment (or the like), a standard and/or mobile webbrowser, an email application (e.g., an email client application), atextual and/or a graphical user interface, a customized web browser, aplugin, an Application Programming Interface (API), or a customapplication. The instruction sets and subroutines of client applications22, 24, 26, 28, which may be stored on storage devices 30, 32, 34, 36,coupled to client electronic devices 38, 40, 42, 44, may be executed byone or more processors and one or more memory architectures incorporatedinto client electronic devices 38, 40, 42, 44.

In some implementations, one or more of storage devices 30, 32, 34, 36,may include but are not limited to: hard disk drives; flash drives, tapedrives; optical drives; RAID arrays; random access memories (RAM); andread-only memories (ROM). Examples of client electronic devices 38, 40,42, 44 (and/or computer 12) may include, but are not limited to, apersonal computer (e.g., client electronic device 38), a laptop computer(e.g., client electronic device 40), a smart/data-enabled, cellularphone (e.g., client electronic device 42), a notebook computer (e.g.,client electronic device 44), a tablet, a server, a television, a smarttelevision, a smart speaker, an Internet of Things (IoT) device, a media(e.g., video, photo, etc.) capturing device, and a dedicated networkdevice. Client electronic devices 38, 40, 42, 44 may each execute anoperating system, examples of which may include but are not limited to,Android™, Apple® iOS®, Mac® OS X®; Red Hat® Linux®, Windows® Mobile,Chrome OS, Blackberry OS, Fire OS, or a custom operating system.

In some implementations, one or more of client applications 22, 24, 26,28 may be configured to effectuate some or all of the functionality ofIO process 10 (and vice versa). Accordingly, in some implementations, IOprocess 10 may be a purely server-side application, a purely client-sideapplication, or a hybrid server-side/client-side application that iscooperatively executed by one or more of client applications 22, 24, 26,28 and/or IO process 10.

In some implementations, one or more of client applications 22, 24, 26,28 may be configured to effectuate some or all of the functionality ofstorage management application 21 (and vice versa). Accordingly, in someimplementations, storage management application 21 may be a purelyserver-side application, a purely client-side application, or a hybridserver-side/client-side application that is cooperatively executed byone or more of client applications 22, 24, 26, 28 and/or storagemanagement application 21. As one or more of client applications 22, 24,26, 28, IO process 10, and storage management application 21, takensingly or in any combination, may effectuate some or all of the samefunctionality, any description of effectuating such functionality viaone or more of client applications 22, 24, 26, 28, IO process 10,storage management application 21, or combination thereof, and anydescribed interaction(s) between one or more of client applications 22,24, 26, 28, IO process 10, storage management application 21, orcombination thereof to effectuate such functionality, should be taken asan example only and not to limit the scope of the disclosure.

In some implementations, one or more of users 46, 48, 50, 52 may accesscomputer 12 and IO process 10 (e.g., using one or more of clientelectronic devices 38, 40, 42, 44) directly through network 14 orthrough secondary network 18. Further, computer 12 may be connected tonetwork 14 through secondary network 18, as illustrated with phantomlink line 54. IO process 10 may include one or more user interfaces,such as browsers and textual or graphical user interfaces, through whichusers 46, 48, 50, 52 may access IO process 10.

In some implementations, the various client electronic devices may bedirectly or indirectly coupled to network 14 (or network 18). Forexample, client electronic device 38 is shown directly coupled tonetwork 14 via a hardwired network connection. Further, clientelectronic device 44 is shown directly coupled to network 18 via ahardwired network connection. Client electronic device 40 is shownwirelessly coupled to network 14 via wireless communication channel 56established between client electronic device 40 and wireless accesspoint (i.e., WAP) 58, which is shown directly coupled to network 14. WAP58 may be, for example, an IEEE 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, Wi-Fi®, RFID, and/or Bluetooth™ (including Bluetooth™ LowEnergy) device that is capable of establishing wireless communicationchannel 56 between client electronic device 40 and WAP 58. Clientelectronic device 42 is shown wirelessly coupled to network 14 viawireless communication channel 60 established between client electronicdevice 42 and cellular network/bridge 62, which is shown by exampledirectly coupled to network 14.

In some implementations, some or all of the IEEE 802.11x specificationsmay use Ethernet protocol and carrier sense multiple access withcollision avoidance (i.e., CSMA/CA) for path sharing. The various802.11x specifications may use phase-shift keying (i.e., PSK) modulationor complementary code keying (i.e., CCK) modulation, for example.Bluetooth™ (including Bluetooth™ Low Energy) is a telecommunicationsindustry specification that allows, e.g., mobile phones, computers,smart phones, and other electronic devices to be interconnected using ashort-range wireless connection. Other forms of interconnection (e.g.,Near Field Communication (NFC)) may also be used.

In some implementations, various I/O requests (e.g., I/O request 15) maybe sent from, e.g., client applications 22, 24, 26, 28 to, e.g.,computer 12. Examples of I/O request 15 may include but are not limitedto, data write requests (e.g., a request that content be written tocomputer 12) and data read requests (e.g., a request that content beread from computer 12).

Data Storage System:

Referring also to the example implementation of FIGS. 2-3 (e.g., wherecomputer 12 may be configured as a data storage system), computer 12 mayinclude storage processor 100 and a plurality of storage targets (e.g.,storage targets 102, 104, 106, 108, 110). In some implementations,storage targets 102, 104, 106, 108, 110 may include any of theabove-noted storage devices. In some implementations, storage targets102, 104, 106, 108, 110 may be configured to provide various levels ofperformance and/or high availability. For example, storage targets 102,104, 106, 108, 110 may be configured to form a non-fully-duplicativefault-tolerant data storage system (such as a non-fully-duplicative RAIDdata storage system), examples of which may include but are not limitedto: RAID 3 arrays, RAID 4 arrays, RAID 5 arrays, and/or RAID 6 arrays.It will be appreciated that various other types of RAID arrays may beused without departing from the scope of the present disclosure.

While in this particular example, computer 12 is shown to include fivestorage targets (e.g., storage targets 102, 104, 106, 108, 110), this isfor example purposes only and is not intended limit the presentdisclosure. For instance, the actual number of storage targets may beincreased or decreased depending upon, e.g., the level ofredundancy/performance/capacity required.

Further, the storage targets (e.g., storage targets 102, 104, 106, 108,110) included with computer 12 may be configured to form a plurality ofdiscrete storage arrays. For instance, and assuming for example purposesonly that computer 12 includes, e.g., ten discrete storage targets, afirst five targets (of the ten storage targets) may be configured toform a first RAID array and a second five targets (of the ten storagetargets) may be configured to form a second RAID array.

In some implementations, one or more of storage targets 102, 104, 106,108, 110 may be configured to store coded data (e.g., via storagemanagement process 21), wherein such coded data may allow for theregeneration of data lost/corrupted on one or more of storage targets102, 104, 106, 108, 110. Examples of such coded data may include but isnot limited to parity data and Reed-Solomon data. Such coded data may bedistributed across all of storage targets 102, 104, 106, 108, 110 or maybe stored within a specific storage target.

Examples of storage targets 102, 104, 106, 108, 110 may include one ormore data arrays, wherein a combination of storage targets 102, 104,106, 108, 110 (and any processing/control systems associated withstorage management application 21) may form data array 112.

The manner in which computer 12 is implemented may vary depending upone.g., the level of redundancy/performance/capacity required. Forexample, computer 12 may be configured as a SAN (i.e., a Storage AreaNetwork), in which storage processor 100 may be, e.g., a dedicatedcomputing system and each of storage targets 102, 104, 106, 108, 110 maybe a RAID device. An example of storage processor 100 may include but isnot limited to a VPLEX™, VNX™, or Unity™ system offered by Dell EMC™ ofHopkinton, Mass.

In the example where computer 12 is configured as a SAN, the variouscomponents of computer 12 (e.g., storage processor 100, and storagetargets 102, 104, 106, 108, 110) may be coupled using networkinfrastructure 114, examples of which may include but are not limited toan Ethernet (e.g., Layer 2 or Layer 3) network, a fiber channel network,an InfiniBand network, or any other circuit switched/packet switchednetwork.

As discussed above, various I/O requests (e.g., I/O request 15) may begenerated. For example, these I/O requests may be sent from, e.g.,client applications 22, 24, 26, 28 to, e.g., computer 12.Additionally/alternatively (e.g., when storage processor 100 isconfigured as an application server or otherwise), these I/O requestsmay be internally generated within storage processor 100 (e.g., viastorage management process 21). Examples of I/O request 15 may includebut are not limited to data write request 116 (e.g., a request thatcontent 118 be written to computer 12) and data read request 120 (e.g.,a request that content 118 be read from computer 12).

In some implementations, during operation of storage processor 100,content 118 to be written to computer 12 may be received and/orprocessed by storage processor 100 (e.g., via storage management process21). Additionally/alternatively (e.g., when storage processor 100 isconfigured as an application server or otherwise), content 118 to bewritten to computer 12 may be internally generated by storage processor100 (e.g., via storage management process 21).

As discussed above, the instruction sets and subroutines of storagemanagement application 21, which may be stored on storage device 16included within computer 12, may be executed by one or more processorsand one or more memory architectures included with computer 12.Accordingly, in addition to being executed on storage processor 100,some or all of the instruction sets and subroutines of storagemanagement application 21 (and/or IO process 10) may be executed by oneor more processors and one or more memory architectures included withdata array 112.

In some implementations, storage processor 100 may include front endcache memory system 122. Examples of front end cache memory system 122may include but are not limited to a volatile, solid-state, cache memorysystem (e.g., a dynamic RAM cache memory system), a non-volatile,solid-state, cache memory system (e.g., a flash-based, cache memorysystem), and/or any of the above-noted storage devices.

In some implementations, storage processor 100 may initially storecontent 118 within front end cache memory system 122. Depending upon themanner in which front end cache memory system 122 is configured, storageprocessor 100 (e.g., via storage management process 21) may immediatelywrite content 118 to data array 112 (e.g., if front end cache memorysystem 122 is configured as a write-through cache) or may subsequentlywrite content 118 to data array 112 (e.g., if front end cache memorysystem 122 is configured as a write-back cache).

In some implementations, one or more of storage targets 102, 104, 106,108, 110 may include a backend cache memory system. Examples of thebackend cache memory system may include but are not limited to avolatile, solid-state, cache memory system (e.g., a dynamic RAM cachememory system), a non-volatile, solid-state, cache memory system (e.g.,a flash-based, cache memory system), and/or any of the above-notedstorage devices.

Storage Targets:

As discussed above, one or more of storage targets 102, 104, 106, 108,110 may be a RAID device. For instance, and referring also to FIG. 3,there is shown example target 150, wherein target 150 may be one exampleimplementation of a RAID implementation of, e.g., storage target 102,storage target 104, storage target 106, storage target 108, and/orstorage target 110. An example of target 150 may include but is notlimited to a VPLEX™, VNX™, or Unity™ system offered by Dell EMC™ ofHopkinton, Mass. Examples of storage devices 154, 156, 158, 160, 162 mayinclude one or more electro-mechanical hard disk drives, one or moresolid-state/flash devices, and/or any of the above-noted storagedevices. It will be appreciated that while the term “disk” or “drive”may be used throughout, these may refer to and be used interchangeablywith any types of appropriate storage devices as the context andfunctionality of the storage device permits.

In some implementations, target 150 may include storage processor 152and a plurality of storage devices (e.g., storage devices 154, 156, 158,160, 162). Storage devices 154, 156, 158, 160, 162 may be configured toprovide various levels of performance and/or high availability (e.g.,via storage management process 21). For example, one or more of storagedevices 154, 156, 158, 160, 162 (or any of the above-noted storagedevices) may be configured as a RAID 0 array, in which data is stripedacross storage devices. By striping data across a plurality of storagedevices, improved performance may be realized. However, RAID 0 arraysmay not provide a level of high availability. Accordingly, one or moreof storage devices 154, 156, 158, 160, 162 (or any of the above-notedstorage devices) may be configured as a RAID 1 array, in which data ismirrored between storage devices. By mirroring data between storagedevices, a level of high availability may be achieved as multiple copiesof the data may be stored within storage devices 154, 156, 158, 160,162.

While storage devices 154, 156, 158, 160, 162 are discussed above asbeing configured in a RAID 0 or RAID 1 array, this is for examplepurposes only and not intended to limit the present disclosure, as otherconfigurations are possible. For example, storage devices 154, 156, 158,160, 162 may be configured as a RAID 3, RAID 4, RAID 5 or RAID 6 array.

While in this particular example, target 150 is shown to include fivestorage devices (e.g., storage devices 154, 156, 158, 160, 162), this isfor example purposes only and not intended to limit the presentdisclosure. For instance, the actual number of storage devices may beincreased or decreased depending upon, e.g., the level ofredundancy/performance/capacity required.

In some implementations, one or more of storage devices 154, 156, 158,160, 162 may be configured to store (e.g., via storage managementprocess 21) coded data, wherein such coded data may allow for theregeneration of data lost/corrupted on one or more of storage devices154, 156, 158, 160, 162. Examples of such coded data may include but arenot limited to parity data and Reed-Solomon data. Such coded data may bedistributed across all of storage devices 154, 156, 158, 160, 162 or maybe stored within a specific storage device.

The manner in which target 150 is implemented may vary depending upone.g., the level of redundancy/performance/capacity required. Forexample, target 150 may be a RAID device in which storage processor 152is a RAID controller card and storage devices 154, 156, 158, 160, 162are individual “hot-swappable” hard disk drives. Another example oftarget 150 may be a RAID system, examples of which may include but arenot limited to an NAS (i.e., Network Attached Storage) device or a SAN(i.e., Storage Area Network).

In some implementations, storage target 150 may execute all or a portionof storage management application 21. The instruction sets andsubroutines of storage management application 21, which may be stored ona storage device (e.g., storage device 164) coupled to storage processor152, may be executed by one or more processors and one or more memoryarchitectures included with storage processor 152. Storage device 164may include but is not limited to any of the above-noted storagedevices.

As discussed above, computer 12 may be configured as a SAN, whereinstorage processor 100 may be a dedicated computing system and each ofstorage targets 102, 104, 106, 108, 110 may be a RAID device.Accordingly, when storage processor 100 processes data requests 116,120, storage processor 100 (e.g., via storage management process 21) mayprovide the appropriate requests/content (e.g., write request 166,content 168 and read request 170) to, e.g., storage target 150 (which isrepresentative of storage targets 102, 104, 106, 108 and/or 110).

In some implementations, during operation of storage processor 152,content 168 to be written to target 150 may be processed by storageprocessor 152 (e.g., via storage management process 21). Storageprocessor 152 may include cache memory system 172. Examples of cachememory system 172 may include but are not limited to a volatile,solid-state, cache memory system (e.g., a dynamic RAM cache memorysystem) and/or a non-volatile, solid-state, cache memory system (e.g., aflash-based, cache memory system). During operation of storage processor152, content 168 to be written to target 150 may be received by storageprocessor 152 (e.g., via storage management process 21) and initiallystored (e.g., via storage management process 21) within front end cachememory system 172.

As noted above, the next generation of storage arrays (e.g., midrangestorage arrays) may support a rich set of data efficiency features,including deduplication, compression, pattern detection, etc. With thedata efficiency features, data may be stored in persistent media in themost efficient form. When replicating or migrating the data, it may bebeneficial to preserve the data in its efficient form, to save networkbandwidth, to speed up replication data transfer, and to potentiallysave precious storage system CPU and memory resources from duplicatingdata efficiency effort at a replication target.

Given that the data is generally not decompressed and/or re-hydratedlocally, context information may need to be saved and provided to ensurelater decompression success, and to perform end to end dataverification. Also, since there may be multiple methods to store dataefficiently, the context information which may need to be saved/providedmay vary significantly. To solve the problem, some existing designs mayfirst introduce several new APIs to retrieve deduplication metadata ofdeduped data blocks, and then retrieve metadata of the compressed datablock, and finally read the compressed data and the uncompressed dataaccordingly. This solution may work, e.g., if deduplication andcompression are only performed when data is written to disk; however, itmay cause missed reads, e.g., if the system performs post processingdeduplication and compression. The latency performance may also beundesirable due to the multiple serialized API calls required. As such,as well be discussed below, the present disclosure enablesself-descriptive data blocks for performing wire efficient IO in asingle API. Generally, “wire efficient” may mean to use the mostbandwidth efficient way to transfer data. For example, compress datafirst before transferring to a remote site. If the data block itself isself-descriptive, then there is no need to add additional APIs (as iscurrently done) to retrieve deduplication metadata, or compressionmetadata, or pattern metadata separately. Moreover, if the data blocksitself is self-descriptive, the associated complexity to connectmetadata with data and to ensure consistency between them may bereduced.

The IO Process:

As discussed above and referring also at least to the exampleimplementations of FIG. 4, IO process 10 may receive 400, by a computingdevice, an IO request. IO process 10 may determine 402 that data of theIO request includes an indication of an attribute. IO process 10 mayconstruct 404 a prefix descriptor for the data in a self-descriptivepage buffer based upon, at least in part, determining that the data ofthe IO request includes the indication of the attribute. IO process 10may call 406 an appropriate Application Programming Interface (API) toprocess the IO request based upon, at least in part, the prefixdescriptor.

As will be discussed below, the present disclosure enablesself-descriptive data blocks for performing wire efficient IOs in asingle API. If the data blocks itself is self-descriptive, then there isno need to add/call additional APIs (as is currently done) to retrievededuplication metadata, or compression metadata, or pattern metadataseparately. Moreover, if the data block itself is self-descriptive, theassociated complexity to connect metadata with data and to ensureconsistency between them may be reduced.

In some implementations, IO process 10 may receive 400, by a computingdevice, an IO request, and may determine 402 that data of the IO requestincludes an indication of an attribute. For example, upon receiving 400an IO (e.g., read) request, as the IO request moves down the virtual andphysical layers of the storage system, IO process 10 may check todetermine 402 whether the requested data includes an indicator that thedata, e.g., is a well-known pattern, has been deduplicated, or iscompressed. A “well-known” data pattern may generally be described asdata that is presented in a repetitive pattern that may be reconstructedby repeating the same pattern. For example, a block of data with all“0”s, or all “1”s, or “101010”, etc. Deduplicated generally means thereare two or more blocks of data with the exact the same content, andstored only one instance. Compressed generally means data that iscompressed to a smaller size.

In some implementations, IO process 10 may construct 404 a prefixdescriptor for the data in a self-descriptive page buffer based upon, atleast in part, determining that the data of the IO request includes theindication of the attribute. For example, after determining 402 that thedata of the IO request includes the above-noted indicator of theattribute that indicates whether the data, e.g., is a well-knownpattern, has been deduplicated, or is compressed, IO process 10 mayconstruct 404 a prefix descriptor (e.g., a data efficiency prefixdescriptor). As will be discussed below, the data efficiency prefixdescriptor may include the type of the attribute, which may include anindication whether the data is a known pattern, whether the data is adeduplicated, and/or whether the data is compressed, and/or whether anyother type of data efficiency has been applied. In some implementations,the prefix descriptor may be in the data block itself or in the pagebuffer (or both). Generally, when in both, the data persisted on thestorage device is considered “self-descriptive”.

In some implementations, the prefix descriptor may be added to the datain the self-descriptive page buffer after compression of the data. Forexample, since the API caller does not know beforehand whether aparticular data block is deduped/compressed, etc., IO process 10 mayhave to allocate a data buffer size for the worst case scenario (e.g.,no data efficiency applied to the requested data). Thus, for data blockswith data efficiency applied (e.g., deduplication, compression, etc.),as long as the constructed 404 prefix descriptor size, plus the payload(e.g., data) size, is less than the data if the data were uncompressed,the saved buffer space from data efficiency features may be used to addspecific metadata (e.g., data efficiency metadata) to the prefixdescriptor of the data. For example, the prefix descriptor of the datafor the page buffer may include, e.g.:

“Magic_number”. This may be a unique number to indicate the headerdefinition and/or embedded header version information. In someimplementations, whenever there is buffer format change, a new magicnumber may be used.

“Buffer-len”. This may indicate the buffer size. In other words, thevalid data length inside the read buffer.

“Original-data_len”. This may indicate the data length of the originaldata (prior to any applied data efficiency), which may be used forvalidation purposes.

“Original-data-checksum”. This may be the checksum of the original pagedata, which may be used for data verification upon data decompression.

“Wire_efficient_type”. This may indicate whether the data has beendeduplicated, compressed, or includes a special well-known pattern.

“Wire-efficient-config”. This may indicate the type specificconfiguration information, deduplication hash algorithm, or compressionalgorithm (e.g., SW or QAI etc.), compression level (e.g., low, medium,high), etc.

“Payload”. This may be the data itself. If the data has beendeduplicated, it may be the full deduplication hash. If the data hasbeen compressed, it may be the compressed buffer. For the pattern, itmay be the pattern signature. It will be appreciated that the names ofthe metadata are for example purposes only and should not be taken tolimit the scope of the present disclosure. Furthermore, differing oradditional metadata may also be used.

In some implementations, IO process 10 may check 408 a bitmap of theself-descriptive page buffer and length of the self-descriptive pagebuffer, and may call 406 an appropriate Application ProgrammingInterface (API) to process the IO request based upon, at least in part,the prefix descriptor, where in some implementations, the appropriateAPI may be a write compressed API when the prefix descriptor indicatescompressed data. For example, with the disclosed self-descriptive databuffer design, the replication service (e.g., via IO process 10) mayonly need to know which pages are compressed, which pages are not, andthe buffer length of the actual data buffer (the above-noted“buffer_len”). For wire efficient data, IO process 10 may send out dataaccording to the actual length (e.g., prefix descriptor size, plus thepayload (e.g., data) size). Otherwise, IO process 10 may send out thewhole page buffer (e.g., 4K page buffer). At the target where the datais to be stored, again, the replication service (e.g., via IO process10) may only need to check 408 the bitmap of the wire efficient page andpage buffer length, and then call 406 the appropriate API (e.g., the“regular” write API (e.g., if the data has not been compressed) or call406 the write compressed API (e.g., if the data has been compressed)).In some implementations, the wire efficient details (e.g., theabove-noted data efficiency metadata) may be hidden inside theself-descriptive page buffer, and only the read/write API implementationmay need to construct and interpret the buffer descriptor.

The terminology used herein is for the purpose of describing particularimplementations only and is not intended to be limiting of thedisclosure. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. As used herein, the language “at least one of A, B,and C” (and the like) should be interpreted as covering only A, only B,only C, or any combination of the three, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps (notnecessarily in a particular order), operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps (not necessarily in a particular order),operations, elements, components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents (e.g., ofall means or step plus function elements) that may be in the claimsbelow are intended to include any structure, material, or act forperforming the function in combination with other claimed elements asspecifically claimed. The description of the present disclosure has beenpresented for purposes of illustration and description, but is notintended to be exhaustive or limited to the disclosure in the formdisclosed. Many modifications, variations, substitutions, and anycombinations thereof will be apparent to those of ordinary skill in theart without departing from the scope and spirit of the disclosure. Theimplementation(s) were chosen and described in order to explain theprinciples of the disclosure and the practical application, and toenable others of ordinary skill in the art to understand the disclosurefor various implementation(s) with various modifications and/or anycombinations of implementation(s) as are suited to the particular usecontemplated.

Having thus described the disclosure of the present application indetail and by reference to implementation(s) thereof, it will beapparent that modifications, variations, and any combinations ofimplementation(s) (including any modifications, variations,substitutions, and combinations thereof) are possible without departingfrom the scope of the disclosure defined in the appended claims.

What is claimed is:
 1. A computer-implemented method comprising:receiving, by a computing device, an IO request; determining that dataof the IO request includes an indication of an attribute; constructing aprefix descriptor for the data in a self-descriptive page buffer basedupon, at least in part, determining that the data of the IO requestincludes the indication of the attribute, wherein the prefix descriptoris added to the data in the self-descriptive page buffer aftercompression of the data; calling an appropriate Application ProgrammingInterface (API) to process the IO request based upon, at least in part,the prefix descriptor; and adding metadata to the prefix descriptor,wherein the metadata is added to the prefix descriptor when the size ofthe prefix descriptor plus the size of a payload is less than the sizeof the data before compression.
 2. The computer-implemented method ofclaim 1 wherein the appropriate API is a write compressed API when theprefix descriptor indicates compressed data.
 3. The computer-implementedmethod of claim 1 further comprising checking a bitmap of theself-descriptive page buffer and length of the self-descriptive pagebuffer.
 4. The computer-implemented method of claim 1 wherein the prefixdescriptor includes a type of the attribute, wherein the attributeincludes an indication whether the data is a known pattern.
 5. Thecomputer-implemented method of claim 1 wherein the prefix descriptorincludes a type of the attribute, wherein the attribute includes anindication whether the data is deduplicated.
 6. The computer-implementedmethod of claim 1 wherein the prefix descriptor includes a type of theattribute, wherein the attribute includes an indication whether the datais compressed.
 7. A computer program product residing on anon-transitory computer readable storage medium having a plurality ofinstructions stored thereon which, when executed across one or moreprocessors, causes at least a portion of the one or more processors toperform operations comprising: receiving an IO request; determining thatdata of the IO request includes an indication of an attribute;constructing a prefix descriptor for the data in a self-descriptive pagebuffer based upon, at least in part, determining that the data of the IOrequest includes the indication of the attribute, wherein the prefixdescriptor is added to the data in the self-descriptive page bufferafter compression of the data; calling an appropriate ApplicationProgramming Interface (API) to process the IO request based upon, atleast in part, the prefix descriptor; and adding metadata to the prefixdescriptor, wherein the metadata is added to the prefix descriptor whenthe size of the prefix descriptor plus the size of a payload is lessthan the size of the data before compression.
 8. The computer programproduct of claim 7 wherein the appropriate API is a write compressed APIwhen the prefix descriptor indicates compressed data.
 9. The computerprogram product of claim 7 wherein the operations further comprisechecking a bitmap of the self-descriptive page buffer and length of theself-descriptive page buffer.
 10. The computer program product of claim7 wherein the prefix descriptor includes a type of the attribute,wherein the attribute includes an indication whether the data is a knownpattern.
 11. The computer program product of claim 7 wherein the prefixdescriptor includes a type of the attribute, wherein the attributeincludes an indication whether the data is deduplicated.
 12. Thecomputer program product of claim 7 wherein the prefix descriptorincludes a type of the attribute, wherein the attribute includes anindication whether the data is compressed.
 13. A computing systemcomprising: one or more memories; and one or more processors configuredto: receive an IO request; determine that data of the IO requestincludes an indication of an attribute; construct a prefix descriptorfor the data in a self-descriptive page buffer based upon, at least inpart, determining that the data of the IO request includes theindication of the attribute, wherein the prefix descriptor is added tothe data in the self-descriptive page buffer after compression of thedata; call an appropriate Application Programming Interface (API) toprocess the IO request based upon, at least in part, the prefixdescriptor; and add metadata to the prefix descriptor, wherein themetadata is added to the prefix descriptor when the size of the prefixdescriptor plus the size of a payload is less than the size of the databefore compression.
 14. The computing system of claim 13 wherein theappropriate API is a write compressed API when the prefix descriptorindicates compressed data.
 15. The computing system of claim 13 whereinthe operations further comprise checking a bitmap of theself-descriptive page buffer and length of the self-descriptive pagebuffer.
 16. The computing system of claim 13 wherein the prefixdescriptor includes a type of the attribute, wherein the attributeincludes an indication whether the data is a known pattern.
 17. Thecomputing system of claim 13 wherein the prefix descriptor includes atype of the attribute, wherein the attribute includes one of anindication whether the data is deduplicated and whether the data iscompressed.
 18. The computer-implemented method of claim 1 wherein thepayload includes a full deduplication hash when the data isdeduplicated.
 19. The computer-implemented method of claim 1 wherein thepayload includes a compression buffer when the data is compressed. 20.The computer-implemented method of claim 1 wherein the payload includesa pattern signature when the data is a known pattern.